div.period_courses {  }
div.period_courses div.period_course h4 { margin-bottom: 4px; }

div.group_wrap { width: 32.28%; float: left; margin-bottom: 5px; margin-right: 0.5%; margin-left: 0.5%; background-color: #dddddd; }
div.group_wrap div.group_name,
div.group_wrap div.group_teaching { background-color: #99ff99; font-size: 1.2em; font-weight: bold; padding: 3px; }
div.group_wrap ul.group_rooms,
div.group_wrap ul.group_students { list-style-type: none; }
div.group_wrap ul.group_rooms li,
div.group_wrap ul.group_students li { padding: 3px 5px; }
div.group_wrap ul.group_rooms li:nth-child(2n),
div.group_wrap ul.group_students li:nth-child(2n) { background-color: #ececec; }
div.group_wrap ul.group_room_teachers { list-style-type: square; margin-left: 25px; }